X-ray free-electron laser induced acoustic microscopy (XFELAM)

Seongwook Choi; Sinyoung Park; Jiwoong Kim; Hyunhee Kim; Seonghee Cho; Sunam Kim; Jaeku Park; Chulhong Kim

doi:10.1016/j.pacs.2024.100587

X-ray free-electron laser induced acoustic microscopy (XFELAM)

Photoacoustics. 2024 Jan 13:35:100587. doi: 10.1016/j.pacs.2024.100587. eCollection 2024 Feb.

Authors

Seongwook Choi¹, Sinyoung Park¹, Jiwoong Kim¹, Hyunhee Kim¹, Seonghee Cho¹, Sunam Kim², Jaeku Park², Chulhong Kim¹

Affiliations

¹ Pohang University of Science and Technology (POSTECH), Medical Device Innovation Center, Department of Electrical Engineering, Convergence IT Engineering, Mechanical Engineering, Medical Science and Engineering, 77 Cheongam-ro, Pohang 37673, Republic of Korea.
² Pohang Accelerator Laboratory, 77 Cheongam-ro, Pohang 37673, Republic of Korea.

Abstract

The X-ray free-electron laser (XFEL) has remarkably advanced X-ray imaging technology and enabled important scientific achievements. The XFEL's extremely high power, short pulse width, low emittance, and high coherence make possible such diverse imaging techniques as absorption/emission spectroscopy, diffraction imaging, and scattering imaging. Here, we demonstrate a novel XFEL-based imaging modality that uses the X-ray induced acoustic (XA) effect, which we call X-ray free-electron laser induced acoustic microscopy (XFELAM). Initially, we verified the XA effect by detecting XA signals from various materials, then we validated the experimental results with simulation outcomes. Next, in resolution experiments, we successfully imaged a patterned tungsten target with drilled various-sized circles at a spatial resolution of 7.8 ± 5.1 µm, which is the first micron-scale resolution achieved by XA imaging. Our results suggest that the novel XFELAM can expand the usability of XFEL in various areas of fundamental scientific research.

Keywords: Accelerator; Photoacoustic; Synchrotron; X-ray; X-ray-induced acoustic; XFEL.